/******************************************************************************
 *    Copyright (C) 2014 Hisilicon STB Development Dept
 *    All rights reserved.
 * ***
 *    Create by Yan Jiantao, Czyong
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *   http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
******************************************************************************/

/*-
 *  COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or
 *  code or tables extracted from it, as desired without restriction.
 */

/*
 *  First, the polynomial itself and its table of feedback terms.  The
 *  polynomial is
 *  X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
 *
 *  Note that we take it "backwards" and put the highest-order term in
 *  the lowest-order bit.  The X^32 term is "implied"; the LSB is the
 *  X^31 term, etc.  The X^0 term (usually shown as "+1") results in
 *  the MSB being 1
 *
 *  Note that the usual hardware shift register implementation, which
 *  is what we're using (we're merely optimizing it by doing eight-bit
 *  chunks at a time) shifts bits into the lowest-order term.  In our
 *  implementation, that means shifting towards the right.  Why do we
 *  do it this way?  Because the calculated CRC must be transmitted in
 *  order from highest-order term to lowest-order term.  UARTs transmit
 *  characters in order from LSB to MSB.  By storing the CRC this way
 *  we hand it to the UART in the order low-byte to high-byte; the UART
 *  sends each low-bit to hight-bit; and the result is transmission bit
 *  by bit from highest- to lowest-order term without requiring any bit
 *  shuffling on our part.  Reception works similarly
 *
 *  The feedback terms table consists of 256, 32-bit entries.  Notes
 *
 *      The table can be generated at runtime if desired; code to do so
 *      is shown later.  It might not be obvious, but the feedback
 *      terms simply represent the results of eight shift/xor opera
 *      tions for all combinations of data and CRC register values
 *
 *      The values must be right-shifted by eight bits by the "updcrc
 *      logic; the shift must be unsigned (bring in zeroes).  On some
 *      hardware you could probably optimize the shift in assembler by
 *      using byte-swap instructions
 *      polynomial $edb88320
 *
 *
 * CRC32 code derived from work by Gary S. Brown.
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

/*****************************************************************************/

#define MAX_ENVITEM_LEN               1024
#define MAX_INPUT_NAMELEN             64
#define MAX_OUTPUT_NAMELEN            64
#define MIN_ENV_SIZE                  0x2000

#ifndef CONFIG_ENV_SIZE
#  define CONFIG_ENV_SIZE             MIN_ENV_SIZE
#endif /* CONFIG_ENV_SIZE */

#define ASSERT(_p) if (!(_p)) { \
	printf("%s(%d): assert: %s\n", __FILE__, __LINE__, #_p);}

#define pr_error(_fmt, args...)  printf("*** " _fmt, ##args)
#define pr_warn(_fmt, args...)   printf("!!! " _fmt, ##args)
/*****************************************************************************/

struct env_t {
	char data[CONFIG_ENV_SIZE - 8];
	unsigned int length; /* the next env string start address */
	unsigned int crc32;
};

static	struct env_t *__env = NULL;

/*****************************************************************************/

static unsigned int crc32_tab[] = {
	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
	0xe963a535, 0x9e6495a3,	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
	0xf3b97148, 0x84be41de,	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,	0x14015c4f, 0x63066cd9,
	0xfa0f3d63, 0x8d080df5,	0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,	0x35b5a8fa, 0x42b2986c,
	0xdbbbc9d6, 0xacbcf940,	0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
	0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,	0x76dc4190, 0x01db7106,
	0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
	0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
	0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
	0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
	0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
	0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
	0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
	0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
	0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
	0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
	0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};
/*****************************************************************************/

static unsigned int crc32(unsigned int crc, const void *buf, unsigned int size)
{
	const unsigned char *p = buf;

	crc = ~0U;
	while (size--)
		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
	return (crc ^ ~0U);
}
/*****************************************************************************/

static char *get_next_item(struct env_t *env, const char *item)
{
	char *lastchr;

	if (!item)
		return env->data;

	ASSERT(item >= env->data);

	lastchr = env->data + env->length;

	ASSERT(lastchr < (char *)&env->length);

	if (item >= lastchr || !*item)
		return NULL;

	while (item < lastchr)
		if (!*item++)
			return (char *)((!*item) ? NULL: item);

	return NULL;
}
/*****************************************************************************/

static char *find_env_item(struct env_t *env, const char *key, char **value)
{
	int length = (int)strlen(key);
	char *item = get_next_item(env, NULL);

	if (value)
		*value = NULL;

	while (item) {
		if (!strncmp(key, item, length) && item[length] == '=') {
			if (value)
				*value = item + length + 1;
			return item;
		}
		item = get_next_item(env, item);
	}

	return NULL;
}
/*****************************************************************************/

static int __env_set(struct env_t *env, const char *key, const char *value)
{
	char *item;
	int newlen;
	int orglen = 0;
	int leavelen;
	char *lastchr = env->data + env->length;

	ASSERT(key != NULL && value != NULL);
	ASSERT(lastchr < (char *)&env->length && !*lastchr);
	ASSERT(!env->length || *(lastchr-2));

	item = find_env_item(env, key, NULL);
	if (item) {
		char *next;

		orglen = strlen(item) + 1;
		next = get_next_item(env, item);
		if (next)
			memcpy(item, next, lastchr - next);

		lastchr -= orglen;
		env->length -= orglen;
	}

	leavelen = sizeof(env->data) - env->length - 2;
	newlen = snprintf(lastchr, leavelen, "%s=%s", key, value) + 1;
	lastchr[newlen] = '\0';
	env->length += newlen;

	if (newlen < orglen)
		memset(lastchr + newlen, 0, orglen - newlen);

	if (leavelen < newlen)
		pr_warn("Input environment out of range, truncated.\n");

	return 0;
}
/*****************************************************************************/

int env_set(const char *key, const char *value)
{
	return __env ? __env_set(__env, key, value) : 0;
}
/*****************************************************************************/

int main(int argc, char *argv[])
{
	char *item;
	char *tmp;
	char input[MAX_INPUT_NAMELEN]   = "input.txt";
	char output[MAX_OUTPUT_NAMELEN] = "bootargs.bin";
	int params = 0;
	const char *delim = "=";
	char *key;
	char *value;

	FILE *fp_input = NULL;
	FILE *fp_output = NULL;

	if (argc != 3) {
		printf("Usage: mkbootargs <input> <output>\n"
			"    Example:./makebootargs input.txt bootargs.bin\n");
		return -1;
	}

	snprintf(input, MAX_INPUT_NAMELEN, "%s", argv[1]);
	snprintf(output, MAX_OUTPUT_NAMELEN, "%s", argv[2]);

	fp_output = fopen(output, "w+b");
	if (NULL == fp_output) {
		perror("open input error.\n");
		return -1;
	}

	fp_input = fopen(input, "rb");
	if (NULL == fp_input) {
		perror("open output error.\n");
		fclose(fp_output);
		return -1;
	}

	item = malloc(MAX_ENVITEM_LEN);
	if (NULL == item) {
		perror("malloc memory error.\n");
		fclose(fp_output);
		fclose(fp_input);
		return -1;
	}

	__env = malloc(sizeof(struct env_t));
	if (NULL == __env) {
		perror("malloc memory error.\n");
		fclose(fp_output);
		fclose(fp_input);
		free(item);
		return -1;
	}

	memset(item, 0, MAX_ENVITEM_LEN);
	memset(__env, 0, sizeof(struct env_t));

	while (fgets(item, MAX_ENVITEM_LEN - 1, fp_input) != NULL) {
		/* delete '\n' of each line. */
		if (item[strlen(item) - 1] == '\n')
			item[strlen(item) - 1] = '\0';
		tmp = item;
		key = strtok(tmp, delim);
		if (!key)
			continue;

		value = item + strlen(key) + 1;
		if (!value)
			continue;

		env_set(key, value);
		memset(item, 0, MAX_ENVITEM_LEN);
	}

	__env->crc32 = crc32(0, __env->data, __env->length);

	/* write data to output */
	fwrite(__env, CONFIG_ENV_SIZE, 1, fp_output);

	free(__env);
	free(item);

	fclose(fp_output);

	if (fp_input != stdin)
		fclose(fp_input);

	return 0;
}
